Apparatus for extracting moisture from compressed air.



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' J.R.DUNOAN.

APPARATES Pea EXTEAIETING MOISTURE PR APPLICATION TILED OUT. 13. 190

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J. R. DUNCAN.

APPARATUS FOR EXTRAOTING MOISTURE FROM COMPRESSED AIR.

APPLICATION FILED 0011a. 1904.

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No. 853,345. PATENTED MAY 14, 1907.

J. R. DUNCAN.

APPARATUS FOR EXTRAGTING MOISTURE FROM GOMPR ESSED AIR. APPLICATION FILED 001. 1a. 1904.

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I @LM 4 5 5 No. 853,345. v PATENTED MAY 14, 1907. J. R. DUNCAN.

APPARATUS FOR EXTRACTING MOISTURE FROM COMPRESSED AIR.

APPLICATION FILED OUT. 13. 1904.

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JAMES R. DUNCAN, OF NEW YORK, N. Y.

APPARATUS FOR EXTRACTING MOISTURE FROM COMPRESSED AIR.

Specification of Letters Patent.

Patented May 14, 1907.

Application filed October 13, 1904 Serial Ila-228,296.

T6 all whom it may concern:

Be it known that 1, JAMES R. DUNCAN, a citizen of the United States, residing at New York, in the county and State of New York, have invented certain new and useful Imrovements in Apparatus for Extracting ioisture from Corn ressed Air and other Gases, of which the ibllowing is aspecification, reference being had to the drawings accompanyin and forming part of the same.

One of t e most serious drawbacks encountered in the use of com ressed air as a motive fluid for operating too s and other. devices is the presence of moisture in the air, which condenses and collects in the utilizing devices and seriously interferes with their operation; In the case of pneumatic tools and other apparatus em loyed out of doors, as in the erection of uildings, work on vessels in drydock, ,etc., this trouble is greatly aggravated in the winter, since in severe weather it frequently happens that the water collected in the tools eezes and thus renders them useless until thawed out. They ma soon freeze up again, however, thusresu ting in annoyance and loss of time. Such annoyance may be very great and widespread, as in the case of a railroad using neumatic switch-operating devices. The

eezin of moisture in the operating mechanism ocks the switch and interferes with or entirely prevents the proper transfer of trains, and may even result in disastrous wrecks. Heating the mechanism to melt the ice is at best a tedious and troublesome operation. Furthermore-,- it does not prevent the device from freezing1 up again when the heat isno longer applie Even wherethere can be no freezing the presence of the water is a disadvantage, since it may cause the operative parts of the'tool or other device to rust,'and cause the apparatus to deteriorate. Such drawbacks can be eliminated only by the use of dry air, and I have therefortalbeen led to devise my present invention, which has'for itsobject to provide an a aratus by which the moisture ma be ii? easily, and cheaply extracted 0m compressed air or other as. To theseends the invention consists o the novel features, arrangements of parts, andco'mbination's of elements hereinafter described, and more. particularly pointed out in the claims.

; whereby In carrying out my invention I cool the compressed air, and thus condense the water vapor which is resent therein, causing the water thus forme to be precipitated in aclosed chamber, leavin the air dry.v While it is true, as a genera roposition, that the vapor of water will con ense at a certain temperature under a given pressure, I have nevertheless fcund that more moisture can be ,removed by heating the air before cooling it, thus indicating that more or less moisture is retained in air which is not heated before being chilled. I am unable to explain this with certainty, but it may be that, while all "the moisture may condensewhether the air has first been heated or not, the considerable drop in temperature, which occurs when the air is heated and then immediately cooled, in some way facilitates the coalescence of the minute particles into larger drops and thus causes a greater or more rapid precipitation. If the particles do not coalesceinto dro s they may remain suspendedin the air and be carried on out of the cooling chamber. But be that as it may, my tests have shown that it is advisable to raise the temperature of the aira few degrees before subjecting it to the cooling agent.

Referring now to the drawings for a more complete understanding of my invention, Figure 1 is a diagrammatic view showing a convenient embodiment of the invention. Figs. 2 and 3 are detail sectional views showing two forms of fleet valve for automatically char ing water from the cooling and collecting 0 amber. Fig. 4is a section on line w-m'. Fig. 3. Fig. 5is a detail view in section, showing a novel form of pressure regulating valve which I em loy in connection with m sgstem, for keeping the pressure of the air t erein constant. Fig. 6 'shows diagrammatically a modification of the system shown in Fig. 1, in which gas is used as a fuel for heating the air, with devices for automatically cutting off the supply of fuel when the' supply of com ressed air is out off. Fig. 7 is a systenrm wiiich electricity is emplo ed to compress and heat the air, with novel evices the pressure of the air and the heating'of't e same are controlled automatically. Fig. 8 is a view showing in detail one of the devices for stopping the compressor and cutting o the current to the heater when the ressure of the air exceeds a predetermined imit.

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Referring to Fig. 1, the air is delivered from any suitable compressor 1, by a pipe 2, to a heating chamber '3. This latter is inclosed within a casing 4, leaving a space between the two as shown, into which a heating medium, such as steam or hot water, is admitted by a ipe 5 connected with a source of supply not shown, and discharged through the pipe 6. Waste steam from a heating or power plant may be conveniently used for such purpose. From the chamber 3, wherein the air is heated, it is carried b the pi'pe7, through valves Sand 9, the va vs 9, being closed, to the discharge pipe 10, from which it issues into the cooling chamber 11. The discharge pipe 1() is preferably provided with a spreader, as the inverted cone 12 placed over the mouth of the pipe, so that the air as it is discharged will be uickly and thoroughly diffused throughout t e chamber and therefore readily cooled. Around the chamber is a casing 13, leaving a space between the two for the circulation of a suitable cooling agent. .Various means may be used to effect the absorption of heat from the air in the chamber 10, as for example a coiled pipe 14, through which ammonia or other rerigerating agent may be passed. I-prefer, however, to use Water as the cooling agent, .and for this purpse I provide a pipe 15, connected to the lower part of the caslng, and to a source of suppl not shown. By connecting the pipe to t e lower part of the caslng the inflow will keep the -water therein con stantl agitatedin that part, and so prevent the eposit of sediment. After passing through the cooling space the water is dis: charged through a pipe 16. be connected to the pipe 15, by a by-pass17 the three pipes bein provided with valves 18, 19, and 20. By 0 osing valves 18 and 19, and opening valve 20, the cooling apparatus will be cut out of the water su ply system, as will be readily understood. ihevalve pipe 19? is for the purpose of draining the cooling space of its contents, when desired, a pet cock 19 being provided in the outer casing to admit air thereto.

As the moisture is precipitated in the cooling chamber it collects in the bottom of the same, from which it may be drawn, ofi from timeto timeas desired. For the purpose of dischar ing the collected moisture auto-. maticall y at suitable intervals I employ a float valve which is normally closed but which is raised when a sufficient quantity ofwater has accumulated to lift the float. Various automatic valves might be used for that pur.

pose. I prefer one or the other of the novel forms shown in i s. 2, 3, and-4. In Fig. 2,

the-float, indicate by 21, isspherical and is located in a casing 22 of corresponding shape.

Depending from the float-is a stem 23, carry ing a conical plug 24, fitting a seat in the diam phragm 25. To insure the. proper seating of.

The latter may the valve plug the stem may ,be provided.

escaping. Besides-being held in its seat by its own weight and the weight of the connected parts, the valve will be held down by the pressure of the air above it, with the result that a greater uantity of water must collect before the va ve will be 0 ened. If the pressure in the chamber 11 18 low the valve may open too frequently, but in that case it may be ,rovided with a spring 29, to hold it more mly in'its seat, as will be readily understood. I Usually, however, the spring will not be found necessary. In the form shown in Figs. 3 and 4, the valve stem and plug 31 are carried. by a perforated disk 32, which is'in turn carried by a tubular ring 33, resting in an annular depression in the valve chamber 34. The annular depres- -sion is connected with the tubular extension 35 by suitable assages, as 36. To insure proper seating o the valve the stem at its upper end is mounted lin a central opening in a guide or spider 37, and at its lower end is pro vided with studs or vanes 38,'which bear on the inner surface of the tubular extension 35. The valve is thus made to move always in the same vertical line. If it is desired. to increase the pressure which holds the plug 31 in its seat a spring 39 may be used between the guide 37 and the disk 32,-as. shown. In order to protect the valve from foreign matter carried in to the chamber 11 by the air, which might lodge-in the valve seat and so interfere with theproper fit of the plug, a screen 40 may be located over the float to prevent such matter from entering the valve chamber.

The outlet valve of the chamber 11 may discharge at any convenient. place, as into a receptacle, or into a Waste pipe 41.

Passing from the cooling chamber by pipe 42, valve 43, and pipe 44, the air is admitted through a'valved pipe into a chamber 46, which serves both as a supplemental cooling chamber and a storage reservoir ortank. It may sometimes happen that some of the particles of water condensed in the main cooling chamber 11 are not precipitated, as might re-- sult from a variety of causes, such-as a con slderable increase in .the temperature of the chamber, but are carried out of the chamber by the outgoing. air.

In that case the par-J tlcles will have further opportunity to coa-' loses in the reservoir 46. By this means; the

last appreciable amount of moisture may be extracted. The water collected in the reservoir may be discharged by an automatic valve in the casing 47, as in the case of the main -cooling chamber, 11, into the same waste pipe 41.

From the reservoir 46 the air is delivered by a pipe 48, valve 49, and pipe to-the point of utilization.

It will be'noted that by the proper use of the various valves in the apparatus any one or all of its parts may be put out of operation. For example, if it is not desired to heat the air, the supply of steam to the jacket 4 may be cut off; the cooling chamber may be disconnected by closing the valves 9 and 43 and opening valve 43;'and the tank 46 may be cut oil by closing the valves in the pipes 45and 48, and o ening'the valve 51.

For the purpose of keeping the pressure of the air substantially constant I employ a governor 52, so connected with the compressing apparatus that increase of pressure above a predetermined limit will cause the compressor to be stopped, or its operation checked, 'until the pressure falls to-normal or below, whereupon the compressor is made to resume its normal operation. A variety of governing devices might be emplo ed for this purpose, but'I prefer to use t e novel devices shown in Fig. 5. The air is admitted through a pipe 53 into the diaphragm chamber 54; W ien. the pressure in this chamber rises above the given limit the diaphragm 55 is raised, carrying with it the valve disk 56 and plug 57. The'latter is provided with a hollow extension 58,. provided with lateralv openings,-as shown, so that the valve stem must rise untilthe apertures are covered by the lower edge ofthe valve seat, before air will be admitted from the'chamber 54 into the pipe 59. Before the air is thus 'admitted, however, the disk 56 has already closed the pipe60, so that the air is compelled'to flow back along the pipe 60. The latter terminates in three branches. The first branch, 61, is connected with a device 62 which is operated by the pressure in the pipe to actuate the valve 63 and cut ofl the supply of compressed air'through the pipe 2; the other branches, 64 and 65, are equipped with similar valve mechanisms, 66, 67, which cut off or reduce the power to the compressor through the pipes 68, 69; thus stoppin the compressor or reducing its output. Suc ivalve operating devices are well known,

' and any convenient form may be used for the pipe 60' passes out through the pipe 60 and passagps 70 to the atmosphere, thus fully relieving t e'pressure'on the .valve operating devices 62, 66, and 67, and restoring the en I It is desirable that the heating chamberand the cooling chamber each be kept at constant temperatures, and for this purpose they may be provided with suitable thermostatic governing devices. I prefer the well known pneumatic system, and in Fig. 1 I have shown such a'system applied to my apparatus. 1* is a pipe extending from the conduit 50 to the thermostat 2, which latter is in a position to be heated by the steam in the jacket 4. When the temperature in the jacket changes, the thermostatic device is actuated, admitting compressed air to the pipe 3, to which are connected the diaphragm valves 4, 5, controlling the steam inlet and outlet pipes. The steamis thereby turned on or oii, as the case may be. The cooling chamber is likewise provided with such devices, as a thermostat 6, controlling the flow of compressed air through the pipe 7*, supplying air to operate the diaphragm valves 8, 9". The latter are shown connected with the ammonia supply and outlet pipes 14, 14*, so that upon variation of temperature in the casing 13 the supply of cold water will be varied accordingly. The thermostat and valves controlled thereby may of course be con' nected with whatever cooling or heating system is used, as will be readily understood. The temperature in the chambers may be shown by thermometers, as 10, 11. The thermostatic devices mentioned are well known and therefore need not be described in detail.

Since steam for heating the compressed air ma not alwa s be available I. havedevised a simple gas eating a paratus which may be installed in lieu of t 1e steam heating de vices. This is shown in Fig. '6. The pipe 2 of the system shown in Fig. 1 communicates with a conical casing or chamber73, which may be cut off at will by valves 74, 75. A

' suitable gas burner 76 is provided for heating the chamber 73, and is connected with a source of gas, not shown, by means of a pipe 77. In the latter is a valve 78, and a pressure actuated device 79 for operating the same which is in communicationwith the pipe 60. It will thus be seen that simultaneously with the closing of ipe 2 and the cutting off of power to the compressor throilgh the pipes 68, 69, the gas to the burner 76 will also be controlled, thereby .pls

avoiding waste of fuel when no air is flowing through the heating chamber 73. It will usually be found preferable to have the valve 78 merely reduce. the amount of'gas to the burner, so that a small flame will contihue to burn. When the normalpressure of the air is restored and, air again begins to flow through the heater 73 the opening of the valve 78 will then at once restore the flame,

Without the necessity of relighting the gas as, would be the case if the valve 78 cut off the supply entirely. A by pass 80 is provided around the valve 78, to increase the supply of gas to the burner when for any reason that may be desirable during the time the valve 78 is closed. The gas supply may be entirely cut off by means of t e valve 81 in thepipe 77.. The conical heating chamber shown in Fig. 6 presents a large heating surface to the gas flame, and'is therefore an economical form, but it'will be understood that other forms may be used if desired.

@Myinvention is well adapted for use with electric power, and in Fig. 7 such a system is shown..-.Anelectric compressor of any convenient type is indicated at 82, current being 96,preferably of the type shown in Fig. 5.

- the heater W1 1 be at the proper temperature deliver air thereto.

Connected with the governors are pressure actuated circuit breakers 97, 98, in the circuits87, 88, and 83, 84 respectively. Fig. 8 shows a convenient circuit breaker which I have devised for that purpose, but other devices may be used if desired. When the compressed air is admitted by the governor through. the pipe 99, upon the diaphragm the latter 1S depressed against the adjustable s ring 101, carrying the stem 102 downward and separating the contacts 103, 104; The latter are in the electrical circuit, as shown, and the current is thereby broken. Upon restoration of normal pressure the diaphragms are released and the contacts again rought together, thus closing the circuit and putting into operation the device actuated thereby. In this way the compressor and heater are controlled in the same wa as in system shown in Figs. 1 and 6. he heater governor is set to close its circuit before the com ressorcircuit isclosed, so that by the'time the compressor againbeginsto Otherwise, if both circuits wereclosed simultaneouslv. the heater gas to the point of utilization, as set forth.

scgple.

- hat I claim is:

1. In an apparatus of the kind described,

the combination with a source of compressed air or other gas, of a heating chamber, means for deliveringthe compressed air or other gas thereto, means for heating said chamber, a

cooling chamber receiving the heated air or other gas from the heating chamber, and means for delivering the cooled air or other 2. In an apparatus of the kind described, the combination with a source of compressed air or other gas, ofa heating chamber, means for delivering the compressed air or othergas thereto, a steam jacket for the chamber to heat the same, a cooling chamber receiving the compressed'air or other gas from the heating chamber, and means for delivering the cooled air or other gas to the point of utilization, as set forth.

3. In an apparatus of the kind described, the combination with a source of compressed air or other gas, of a heating chamber, a

source of heat therefor, a cooling chamber.

means for delivering the compressed gas from the heatingchamber to the cooling chamber,

automatic means for controlling thesource of compressed gas and the source of heat when the pressure of the compressed gas varies from a predetermined limit, and ,means for delivering the compressed gas to the point of utilization, as set forth.

4.- In an apparatus of the kind described, the combination with a source of compressed air or other gas, of a heating chamber, a source of heat therefor, a cooling chamber,

means for delivering the compressed gas from the heating chamber to the cooling chamber, means for controlling the source of -heat, means for controlling the source of compressed gas, both said controlling means being operated by the compressed gas in the system, automatic means for'putting both said controlling means into operation when the pressure in the system varies from a predetermined limit, and means for delivering the compressed gas to the point of utilization, as set forth. a

5. In an apparatus of the kind described, the combination with asourceof compressed air or other gas, of a heating chamber, a source of heat therefor, a cooling chamber,

means for delivering the compressedgas from I,

the heating chamber to the cooling chamber, means for controlling the (source of heat,

means tor controlling the source of comand means for delivering the compressed gas pressed gag, bolthsaid controcllling means being to the point of utilization, as set forth.

0 erate y t e com resse gas inthe s st m, a governor, actuated by the compres ed JAluEb DUNCAD" gas in the system when the i'essure therein Witnesses: varies from a predetermined l1mit,for putting HENRY J. MULLEN. both said controlling means into operation, \V. U. FREDERICK. 

